Suicidal Thoughts, Behaviors, and Event-Related Potentials: A Systematic Review and Meta-Analysis

Background: Suicidal thoughts and behaviors (STBs) are thought to be the result, at least in part, of abnormalities in various neural systems. Event-related potentials (ERPs) are a useful method for studying neural activity and can be leveraged to study neural deficits related to STBs; however, it is unknown how effective ERPs are at differentiating various STB groups. The present meta-analysis examined how well ERPs can differentiate (a) those with and without suicidal ideation, (b) those with and without suicide attempts, (c) those with different levels of suicide risk, and (d) differences between those with suicide attempts versus those with suicidal ideation only. Method: Our meta-analysis included 208 effect sizes from 2,517 participants from 27 studies. We used a random-effects meta-analysis using a restricted maximum likelihood estimator with robust variance estimation. Results: Our qualitative review found that for each ERP and STB combination, the literature is highly mixed. Our meta-analyses found a small-to-moderate relationship between ERPs and suicidal ideation, suicide attempt, suicide risk, and differences in ERPs between those with suicide attempts versus those with suicidal ideation only. We also found evidence that the literature may be suffering from small-sample bias and poor statistical power. Conclusions: Our results suggest that ERPs may complement other approaches, such as fMRI, in the study of the neurobiology of individuals with STBs. However, the current literature is severely underpowered to detect the effect sizes estimated in this meta-analysis. We recommend large-scale collaboration and improvements in measurement practices to combat the issues in this literature.